1. Field of the Invention
The present invention relates to a startup control technique of a storage device in an electronic apparatus which comprises a communication function, and can be driven by, e.g., a battery.
2. Description of the Related Art
In recent years, portable electronic apparatuses such as personal digital assistants (PDAs), which can be powered by batteries, have prevailed. Most such electronic apparatuses have a wireless communication function. Upon receiving data using this wireless communication function, the received data is buffered in a random access memory (RAM), and is saved on a magnetic disk accordingly when the load on the CPU is low.
In an electronic apparatus which operates on power from a battery, various methods for saving power have been devised to assure the longest possible operating time. For example, Japanese Patent Application No. 2001-333055 discloses the following technique in place of the conventional method for saving received data, which is buffered in a RAM, on a magnetic disk accordingly when the load on the CPU is low. That is, the saving process is delayed until the RAM is full of data, and the received data is saved in a single operation at the time when the RAM becomes full of data, thus achieving power saving for a magnetic disk device (to be referred to as an HDD hereinafter) used to write data on a magnetic disk. Therefore, by applying this technique, the HDD is started up only when data is saved on the HDD, i.e., only when necessary. Hence, not only power consumption required to make a write access to the HDD can be saved but also further power savings can be achieved.
It should be noted that the HDD requires a relatively long time until it is started up. Therefore, when such power savings are to be achieved, if the HDD is started up during data reception of the wireless communication function, the data reception must be suspended from when the RAM is full of data until the HDD is started up.